Quick opening die head with chaser adjusting means for different size pipes



May 31, 1960 B. G. BJALM E QUICK OPENING DIE HEAD TH ASER ADJUSTING MEANS FOR DIFFEL T E PIPES Filed Feb. 17, 1958 2 Sheets-Sheet 1 IN V EN TOR.

y 1960 B. s. BJALME 2,938,222

QUICK OPENING DIE HEAD WITH CHASER ADJUSTING mums FOR DIFFERENT SIZE PIPES 2 Sheets-Sheet 2 Filed Feb. 17. 1958 I INVEN TOR.

United States Patent QUICK OPENING DIE HEAD WITH CHASER AD- JUSTING MEANS FOR DIFFERENT SIZE PIPES Bengt G. Bjalme, Erie, Pa., assignor to Reed Manufactut-ing Company, Erie, Pa., a corporation of Pennsylvama Filed Feb. 17, 1958, Ser. No. 715,807

4 Claims. (Cl. 10-122) This invention is a quick opening threader on which the user can quickly select the size to be threaded and can adjust the selected size for over and under size threads. The accuracy of both the size selection and adjustment is determined by the construction and is not affected by the judgment of the user.

In the drawing, Fig. 1 is a front view of a quick opening pipe threader; Fig. 2 is a section on line 2-2 of Fig. 1; Fig. 3 is an edge view of the mechanism for size selection and adjustment; Fig. 4 is a section through the mechanism; and Fig. 5 is an exploded view of the mechanism.

The conventional elements of the threader are readily identified, 1 being the frame with radial slots 2 for threading chasers 3 and 4 being a scroll plate journalled on the frame and having spirally directed cam elements 5 fitting in notches 6 in the chasers and moving the chasers radially as the scroll plate is rotated on the frame. The parts so far described are or may be of common construction. A specific structure is described in detail in my application Serial No. 591,104 now US. Patent No. 2,855,611, issued October 14, 1958.

In the use of the threader, the scroll plate 4 is rotated relative to the frame 1 for a number of reasons. When the threader is used to thread a number of pieces of the same size, the rotation of the scroll plate 4 is for the purpose of opening and closing the threader. The threader is closed at the start of each threading operation and is opened to move the chasers outward to clear the threads at the end of each threading operation. Another circumstance which requires rotation of the scroll plate relative to the frame is when the threader is to be used to cut threads of a different diameter. Still another circumstance requiring rotation of the scroll plate is when the chasers are to be adjusted to cut threads which are either over size or under size. All of these circumstances commonly occur during the use of the threader.

The opening and closing of the threader is under the control of a toggle comprising links 7 and 8 pivoted to each other at 9 and movable between a folded position in which the die is closed and an extended position in which the die is open. In both the folded and extended positions, the toggle links 7 and 8 are in a stable position substantially in line with each other and extend in a direction tangential to an are centered on the axis of the threader. The toggle links are moved between open and closed position by a handle 10 integral with one of the toggle links.

The toggle link 8 has fixed thereto a pin 11 journaled in a socket 12 in an eccentric 13. The socket 12 is spaced from the center of the eccentric 13 so that as' the eccentric is turned the pin 11 and the toggle link 8 are moved by the eccentric. This is used to obtain a fine adjustment of the scroll plate such as is needed to cut threads which are slightly over or slightly under standard size. This may be necessary, for example, in pipe which must be used with fittings which do not have standard size threads. The eccentric 13 is journaled in 2,938,222 Patented May 31, 1960 "ice of a socket 23 in a latch member 24 urges the tapered end 25 of the latch member into any selected one ofchamfered notches 26 spaced along an arcuate slot 27 in the frame member 1. In the engaged position, the tapered end 25 of the latch member 24 centers the pin 19 in a position in which it fits in the selected notch 28. This positively locates the pivot for the toggle link 7 on the frame member 1. The notches 28 are spaced along the slot 27 at distances corresponding to the size of thread to be cut. So long as the latch member 24 is in the engaged position, the threader cuts the size of thread corresponding to the selected notch 28. To change the thread size, the latch member 24 is retracted by gripping a flange 29 and moved outward until its tapered end 25 is clear of the chamfered notch 26. In this position, the pin 19 can easily be lifted out of the notch 28 and slid along the slot 29 until it reaches the notch 28 corresponding to the new size to be threaded. It is not necessary that the pin 19 be precisely lined up in the proper location in the slot 27 because as soon as the latch member 24 is released, the spring 21 forces the tapered end 25 of the latch member into the chamfer 26 and automatically centers the pin in the proper position to cut the new size of thread. When the latch member is re-engaged, the primary thrusts are taken between the pin 19 and the notch 28. Because the latch member 24 is at one end of the toggle link 7, it is easy to lift the pin 19 out of the notch 28 and slide it along the slot 27.

In this pipe threader, the various operations are independent of each other. The opening and closing movement of the threader is determined by the length of the toggle links 7 and 8. This remains unchanged. The selection of the size of thread is determined by the latch member 24 co-operating with the notches 26, 28 along the slot 27. These notches are accurately positioned in the manufacturing operation. No judgment on the part of the user is required to change thread sizes. The fine adjustment which permits the cutting of threads over or under size compared to standard is independent of the other adjustments. The amount of over or under size is selected by turning the knob 15 with reference to an index mark 30 on the boss '14. There again the judgment of the user is not required because the 'knob 15 is moved in steps determined by the detent 16. The operator may turn the knob 15 one, two, or more steps in the direction to cut threads which are smaller or larger than standard but no matter who turns the knob, the amount of fine adjustment is the same. The accuracy of the fine adjustment is determined by the spacing of the recesses 16a which are engaged by the detent 16.

What is claimed as new is:

1. In a quick opening threading die of the type having a frame carrying radially movable thread cutting chasers, and a scroll plate journaled on the frame for moving the chasers radially, said frame and scroll plate comprising relatively movable members, an eccentric journaled in one of the relatively movable members, a handle for rotating the eccentric, a toggle link having one end pivoted on the eccentric at a point spaced from its center whereby the link is movable by the eccentric, another toggle link pivoted to the other end of the first link and to a pin, said other member having an arcuate slot concentric with the axis of the threader, said pin being slidable along the slot, latch means comprising a part carried by the pin and a plurality of complementary latch structures spaced along the slot and each corresponding to a different size of thread and being selectively engageable by said part for holding the pin in any one of the selected sizes, and means for rotating the toggle links between extended and folded positions to open and close the die, the movement of the first toggle link by the eccentric providing a supplemental adjustment of the radial position of the chasers.

2. In a quick opening threading die of the type having a frame carrying radially movable thread cutting chasers, and a scroll plate journaled on the frame for moving the chasers radially, said frame and scroll plate comprising relatively movable members, an eccentric journaled in one of the relatively movable members, a handle for rotating the eccentric, a toggle link having one end pivoted on the eccentric at a point spaced from its center whereby the link is movable by the eccentric, another toggle link pivoted to the other end of the first link and to a pin, said other member having an arcuate slot with notches along one side of the slot spaced in accordance with the thread size, said pin being slidable along the slot and receivable in any selected one of the notches, means for holding the pin in the selected notch, and means for rotating the toggle links between extended and folded positions to open and close the die, the movement of the first toggle links by the eccentric providing a supplemental adjustment of the radial position of the chasers.

3. In a quick opening threading die of the type having a frame carrying radially movable thread cutting chasers, and a scroll plate journaled on the frame for moving the chasers radially, said frame and scroll plate comprising relatively movable members, a pair of toggle links pivoted to each other and movable between a folded position and an extended position, the links in both positions being generally tangential to an are centered on the axis of the cutter, one of the toggle links being pivoted to one of the members, the other toggle links being pivoted on a pin, the other member having an arcuate slot concentric with the axis of the threader, said pin being slidable along the slot, latch means comprising a part carried by the pin and a plurality of complementary latch structures spaced along the slot and each corresponding to a difierent size of thread and being selectively engageable by said part for holding the pin in any one of the selected sizes, and means for rotating the toggle links between extended and folded positions. to open and close the die.

4. In a quick opening threading die of the type having a frame carrying radially movable thread cutting chasers, and a scroll plate journaled on the frame for moving the chasers radially, said frame and scroll plate comprising relatively movable members, a pair of toggle links pivoted to each other and movable between a folded position and an extended position, the links in both positions being generally tangential to an are centered on the axis of the cutter, one of the toggle links being pivoted to one of the members, the other toggle links being pivoted on a pin, the other member having an arcuate slot with notches along one side of the slot spaced in accordance with the thread size, said pin being slidable along the slot and receivable in any selected one of the notches, means for holding the pin in the selected notch, and means for rotating the toggle links between extended and folded positions to open and close the die.

References Cited in the file of this patent UNITED STATES PATENTS 1,592,245 Williams July 13, 1926 1,804,708 Schumacker May 12, 1931 2,557,040 Strickland June 12, 1951 2,588,932 Klingenberg Mar. 11, 1952 2,645,021 Dierkes July 14, 1953 2,680,256 Ingwer June 8, 1954 2,688,289 Sterling Sept. 7, 1954 2,885,698 Bjalme May 12, 1959 FOREIGN PATENTS 1,108,970 France Sept. 14, 1955 

